Wide agricultural implements typically include wing frames extending laterally from a center of the implement where each wing frame is pivotally attached to the adjacent wing frame about a horizontal pivot axis aligned with the operating travel direction such that each wing frame can pivot up and down with respect to the next to follow ground contours and maintain a desired depth of ground penetration of ground engaging tools such as furrow openers.
It is common to fold the wing frames upward and inward to a more compact transport position as disclosed in U.S. Pat. No. 6,684,962 to Lewallen, however with wider implements the implement in the transport position can be quite high causing stability problems as well as making same difficult to move under utility lines, bridges, and the like.
Thus it is also known to fold the wing frames rearward as disclosed for example in U.S. Pat. No. 7,581,597 to Neudorf et al., U.S. Pat. No. 8,567,517 to Friggstad et al., and U.S. Pat. No. 9,198,342 to Friggstad. With an implement such as an air seeder it is common to pull a cart behind the implement to supply agricultural products such as seed and fertilizer. These carts can be very large and must be towed rearward of ends of the wing frames in the transport position which is a significant distance from the towing tractor such that stability during towing can be problematic.
It is also known to fold the wing frames of agricultural implements forward to a more compact transport position however the width of the implement is limited by the length of the hitch. In order to accommodate wider implements the hitch length can be extended when in the transport position, as disclosed in U.S. Pat. No. 6,371,216 to Friggstad and U.S. Pat. No. 9,554,497 to Sudbrink et al. and in United States Published Patent Application Number 20070163791 of Meek.
Such telescoping hitches require considerable added material to provide the required strength to resist the forces exerted on the hitch, and lock mechanisms are required to secure the hitch in the extended and retracted positions which must be engaged and disengaged when moving between the operating and transport positions, adding time and complexity. This telescoping also adds complexity when locating hydraulic lines from the tractor to the implement, product lines for air seeders, and the like.
In such forward and rearward folding implements the implement typically comprises a tool bar extending laterally with the desired number of wing frames, and then tool carrier frames pivotally mounted to the tool bar such that the carrier frames extend generally horizontally from the tool bar when in the operating position and upward when in the transport position. The carrier frames can extend horizontally rearward of the tool bar as in U.S. Pat. No. 7,581,597 to Neudorf et al., U.S. Pat. No. 8,567,517 to Friggstad et al., or forward of the tool bar as in U.S. Pat. No. 9,198,342 to Friggstad.
Ground engaging tools such as furrow openers are attached to each carrier frame and are moved into and out of engagement with the ground surface. In the implement of U.S. Pat. No. 8,567,517 to Friggstad et al. each ground engaging tool is pivotally attached to the carrier frame which remains horizontal and stationary at a defined vertical location with respect to the ground when in the operating position. The ground engaging tools pivot up and down with respect to the carrier frame to engage or disengage the ground. In the implement of U.S. Pat. No. 6,371,216 to Friggstad, the ground engaging tools are fixed to the carrier frame which is maintained at a horizontal orientation and moved up and down to engage and disengage the tools with the ground.